Focus Trial Version for iOS / OS X
As you may know the App Store and Mac App Store does not offer trials and since Focus is using iCloud to sync everything, it's not possible to offer a non-Mac App Store version of Focus. I'm sorry.
I try to add a non-iCloud version for your to try out in the future but since there are so many other things to do at the moment, this may take a while.
However, there are two short videos available that show Focus in action:
Focus for Mac OS X
Focus for iOS and Apple Watch
Maybe it gives you an impression how Focus works. If you have more questions, please let me know.